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Message-ID: <19f34abd0806301143u2067d593kf162d7419b653a8b@mail.gmail.com>
Date: Mon, 30 Jun 2008 20:43:25 +0200
From: "Vegard Nossum" <vegard.nossum@gmail.com>
To: "Ingo Molnar" <mingo@elte.hu>
Subject: Re: [git pull] core kernel fixes
Cc: "Linus Torvalds" <torvalds@linux-foundation.org>,
       linux-kernel@vger.kernel.org,
       "Andrew Morton" <akpm@linux-foundation.org>,
       "Thomas Gleixner" <tglx@linutronix.de>,
       "Daniel J Blueman" <daniel.blueman@gmail.com>
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On Mon, Jun 30, 2008 at 8:20 PM, Ingo Molnar <mingo@elte.hu> wrote:
> The patch was tested with our standard tests so it's certainly good in
> practice - but i havent specifically tried your testcase (maybe Thomas
> has). Can you see any problem with the fix?

Well, what I can see is that the patch that was committed has some
missing changes. In Daniel's patch:

-repeat:
-	spin_lock(&pool_lock);
+	spin_lock_irqsave(&pool_lock, flags);
 	if (obj_pool.first) {
 		obj	    = hlist_entry(obj_pool.first, typeof(*obj), node);

The patch that was committed:

-repeat:
        spin_lock(&pool_lock);
        if (obj_pool.first) {
                obj         = hlist_entry(obj_pool.first, typeof(*obj), node);

Was it not necessary to make the pool lock irq-safe in this place?

For reference:

Daniel's patch: http://lkml.org/lkml/2008/6/15/27
Actual commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=70c85057e0bde35eb56352a293ecb5d1641a0334;hp=e6100f23375c0c71ce595d04551fa6553b611918


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036